1. Field of the Invention
The present invention relates to a protective device, more specifically, to a protective device for a tube on a plasma display panel.
2. Description of the Prior Art
A plasma display panel (PDP) generates its images through discharge of gas. Within the PDP is a space, micrometers in size, coated with fluorescent cells and filled with discharge gas. When a voltage is applied to the discharge gas, a discharge occurs within the gas to generate ultraviolet (UV) radiation. The UV radiation causes each fluorescent cell to emit one of the primary colors, red, green or blue. Hence, with the proper combination of cells and their associated colors, a bright and vivid image is displayed.
Please refer to FIG. 1 of a perspective view of a tube 18 of a PDP 10 according to the prior art. The plasma display panel 10 comprises a front plate 12 and a rear plate 14. In the prior art manufacturing method for a PDP 10, the front panel 12 and the rear panel 14 are first produced respectively and then sealed together. Then, air is extracted from the space between the two panels and then the space is filled with a mixture of dischargeable gas such asNeon and Xenon. The sealed PDP 10 is then assembled with other components and is packaged within a housing to form an end product.
According to the prior art, an air hole is positioned at a corner edge of the rear panel 14, surrounded by a doughnut-shaped base 16. During the sealing process, a tube 18 is fixed to the base 16 for extracting gas out of the space between the two panels 12, 14 and inputting gas mixture into the space. After inputting sufficient gas mixture, the tube 18 is cut to reduce its length and melted to seal the space between the front panel 12 and rear panel 14 of the plasma display panel 10 for the subsequent assembly process.
Due to protrusion of the tube 18 of the PDP 10, the PDP 10 may break easily during the process of delivery and storage, resulting in defects in the PDP 10. Once breakage of the tube 18 occurs, the Neon and Xenon gas mixture within the PDP 10 is released to allow entry of outside air particles, thereby polluting the PDP 10. Even if the tube 18 is re-sealed, the performance of the PDP 10 still decreases due to the prior leakage of the gas mixture and entrance of outside air particles. Thus, a protective device is required to prevent breakage of the tube 18 of the PDP 10 caused by an impact of an external force.
It is therefore a primary object of the claimed invention to provide a protective device for a tube on a PDP to prevent tube breakage due to an impact of an external force, thereby maintaining the quality of the PDP.
According to the claimed invention, the protective device is used for a tube bonded on a plasma display panel (PDP). The PDP comprises a plate which does not break when experiencing a first force, anair hole for passing air above and below the plate and in air communications with the tube, and a doughnut-shaped base disposed around the air hole and the tube. The protective device comprises a hollow shield with a first opening on a bottom end bonded to the doughnut-shaped base for containing the tube, and a binding compound for binding the hollow shield to the doughnut-shaped base. The hollow shield remains bonded to the doughnut-shaped base when experiencing a second force which is smaller than the first force. When the hollow shield experiences an external force greater than the second force, the hollow shield will separate from the doughnut-shaped base without breaking the plate.
It is an advantage of the claimed invention that the use of the protective device can effectively protect the tube and the plate from being damaged by an external force.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings.